Barking machine



1953 TOR OVE HILLBOM 2,6 7,

BARKING MACHINE Filed March 22, 1949 V Inventor: 3 1 m O\(e Hmbom Attorng Patented Nov. 3, 1953 UNITED STATES 1 PATENT OFFICE Tor Ove Hillbom, Rottneros, Sweden Application March 22, 1949, Serial No. 82,747

cause of friction between the logs, while they are caused at the same time to circulate and to become rearranged within the pile. Barking machines of this type are previously known, wherein said motion members consist of endless chains or the like, which are provided with members projecting into the pile and permitting 1 the lower logs to moveat a smaller speed than the chains so as to bring about a pulsating movement of the logs at right angles to the longitudinal direction of the same. A motion mechanism of this kind is composed of a great number of parts and is consequently subjected to severe wear and disturbances.

The present invention is principally distinguished by the feature that the motion members are constituted by a number of rotatably mounted helically shaped rollers, which are arranged in an inclined position with their longitudinal axes extending in the transverse direction of the logs. A motion mechanism of this kind is constructively simpler and stronger than the known chain mechanisms, and, furthermore, it has a, barking effect considerably higher than that of said known mechanisms. By the fact that the logs engage the thread-shaped surfaces of the rollers, the logs will be subjected to forces not only in the transverse direction but in the longitudinal direction as well,flwhereby the bark will be subjected to shearing forces that facilitate loosening of the same. By selecting the pitch of the thread sufliciently great to permit the logs to fall into the intervening spaces between the threads, the lower logs in the pile will be permitted under the influence of the weight of the logs lying over the same to perform a rotary movement about their longitudinal axes as well as a pulsating transverse movement at concurrent feeding of the logs in the longitudinal direction of the rollers. To this end, the rollers are preferably given a thread profile with a rounded thread top fitting to the cylindrical shape of the logs.

The forces acting in the longitudinal direction of the logs may also be utilized to bring about a longitudinal movement of the logs. For this purpose the rollers are preferably threaded 1 Claim. (01. 144-208) groupwise in opposite directions and arranged to rotate in opposite directions. For example, the rollers rotating in opposite directions may be distributed in two groups arranged on both sides of the midplane of the container, the rollers then tending to displace the logs in the longitudinal direction toward the center of the pile and the container. This movement, which particularly manifests itself when the machine operates with small quantities of lumber in the container, has the effect of preventing the formation of heaps, inasmuch as shorter logs that fall down beside the one head wall of the container tend to move toward the center of the pile. Said longitudinal movement also has an advantageous effect on the barking operation. This effect is ascribable to the fact that the forces exerted by the roller threads impart a certain reciprocatingmovement to the logs in the longitudinal direction thereof, depending on the fact that the logs are not entirely cylindrical or straight, and will consequently rest periodically on a varying number of right-handed and lefthanded screw threads. To utilize this barking effect, the container holding the logs should have a width exceeding the length of the logs.

The invention will be described more closely with reference to the accompanying drawing.

Fig. 1 shows a vertical section through a barking machine according to a form of embodiment of the invention, and Fig. 2 is a plan view of the machine.

The container holding the logs consists of a front end masonry wall on a foundation l5, of a rear end supporting wall I and of two parallel side walls 2, 3. The bottom of the container is formed by a number of screw-shaped rollers 4,

5, which are rotatably mounted at their ends and arranged in a mutually parallel relationship with their longitudinally extending axes located in an inclined plane. These rollers form a movable supporting structure for the logs 6, which are laid up in the container so as to form a pile with the logs lying transversely over the rollers. The logs are introduced into the container by means of an elevator l. The direction of rotation of the rollers and the direction of the threads are such that the rollers tend to convey the logs bearing thereon in a transverse direction from below and upwardly. The logs are thu moved against a baflie in the form of a gate 9 pivoted about an axis 8, said gate damming up the logs and thus compelling them to roll back down toward the lower ends of the rollers. The logs will thus circulate within the pile while be- 3 ing incessantly rearranged, the barking being effected thereat through the friction between the logs. The barking operation having been terminated, the container is emptied by the opening of the gate 9, which is adapted to be shifted by means of a motor ID, the shaft H of which transmits the movement to the rotary shaft 8 of the gate by means of a pinion l2 and a toothed segment [3. During the barking operation water is supplied through a pipe l4 having a spreader nozzle arranged thereon.

The container I, 2, 3 and the rollers 4, 5 are arranged on the concrete foundation IS, the portion of the same located underneath the rollers forming a collecting chute l6 for the bark, which is washed away 'by a supply of flushing water entering through a pipe H. The rollers 4-, i are mounted at one end thereof in bearings, 18 on the concrete foundation and at the other end thereof in bearings 19 arranged in the wall I. The rollers are driven by an electric motor 20 through the intermediary of a shaft 2| and a number of worm gearings 22 individually allotted to the various rollers. A bafile plate 24 arranged on the roller shaft 23 prevents water from flowing down onto the worm gearing,

The rollers 4', 5 consist of helically shaped sleeves from cast iron, said sleeves being arranged on the shafts 23. The pitch of the roller threads is sufiicient to permit the logs to fall into the intervening spaces between the threads, and the thread profile is such as to cause the threads to fit the substantially cylindrical surface of the logs. By giving the threads a rounded top configuration and by otherwise adapting the shape of the thread and the inclination of the rollers in a suitable manner, the logs bearing on the rollers will be caused to move upwardly at a rate falling below the speed represented by the thread pitch times the rotary speed of the rollers. Consequently, the logs will at the same time have a pulsating movement imparted to them at right angles to the rollers, whereby the barking operation is facilitated.

The number of rollers depends onthe length-of the logs. In the example shown, the supporting structure of the logs is constituted by six rollers distributed in two groups 4, 5 on both sides of the vertical midplane of the container, the

rollers in the two groups being threaded in opposite directions and adapted to rotate in opposite directions. Hereby logs which have been displaced against one of the walls will tend to settle at the center of the pile and the receptacle. It is not necessary, however, to arrange the rollers in two groups in the manner shown in Fig. 2', it being possible to distribute the oppositely threaded and oppositely rotating rollers in other ways, for instance so that the rollers of each pair of adjacent rollers are threaded and rotate in opposite directions.

The rollers are preferably arranged to rotate at the same speed, all of the rollers having then the same thread pitch, so that forces exerted by the rollers in the axial direction become uniformly distributed all over the length of the logs. The mutual angular positions of the rollers should then also be such that the individual logs may engage the threads of all of the rollers at the same time.

I claim:

Abarking machine comprising a log container having parallel side walls and two end walls, 102 charging means at one end of said container, log discharging means at the opposite end of said container, an inclined bottom structure consisting of a plurality of helically threaded rollers extending longitudinally and in parallel inclined relationship-between said two end walls, and comprising two groups of rollers arranged one on each side of that mid-plane of the log container interseating the end walls, the rollers of each group bein threaded in the same direction and the rollers of different groups being threaded in opposite directions, means for rotating the rollers of each grou in the same direction, and means for rotating the rollers of different groups in opposite directions, whereby to cause logs piled up transversely of the rollers to be moved toward the outlet end of the container while being repeatedly engaged by the threads of the rollers, whereby to effect both a longitudinal and a lateral reciprocating action on'said logs.

TOR OVE I-IILLBOM.

References Cited in the file of this patent UNITED STATES PATENTS FOREIGN PATENTS Country Date. Sweden Feb. 13, 1918 Sweden 1936 Sweden Dec. 9,, 1947 Great Britain Apr. 23, 1925 Number Number 

